Field of the Invention
The present invention relates to an imaging apparatus having an imaging element.
Description of the Related Art
According to an imaging element which is mounted in an imaging apparatus such as a digital video camera, digital still camera, or the like, in recent years, an ISO sensitivity has risen and, even in a scene of a small light amount such as a night scene, imaging with a clearer image can be performed. However, in association with the realization of the high sensitivity of the imaging element, such a problem that the imaging element is influenced by weak noises which did not cause a problem in the related art and a disturbance occurs in the image is actually caused.
For example, in the digital video camera, a motor for driving a lens is arranged in front of the imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or the like. Since a coil is provided for the lens driving motor, there is a case where a magnetic field generated from the coil exerts an influence on the imaging element and a disturbance occurs in the image which is formed by the imaging element.
In the related arts, with respect to a technique for suppressing such a situation that magnetic field noises generated from the coil are superimposed into the imaging element, Japanese Patent Application Laid-Open No. 2014-060676 discloses such a construction that a ferromagnetic member made of a ferromagnetic material having a high relative permeability such as Permalloy or the like is arranged between the coil and the imaging element. According to the construction disclosed in Japanese Patent Application Laid-Open No. 2014-060676, the ferromagnetic member becomes a detour of a magnetic flux to the imaging element and an arrival amount of the magnetic flux generated from the coil which arrives at the imaging element is reduced.
However, if the ferromagnetic member is arranged between the coil and the imaging element as disclosed in Japanese Patent Application Laid-Open No. 2014-060676, the ferromagnetic member also approaches inevitably the imaging element. The ferromagnetic member serving as a detour of the magnetic flux does not perfectly shut off the magnetic flux and a leakage of the magnetic flux exists in the neighborhood. Therefore, there is such a problem that if the ferromagnetic member approaches the imaging element, an amount of magnetic field which arrives at the imaging element increases.
According to such a construction that two coils are arranged so as to sandwich an imaging element, there is a case where a ferromagnetic member arranged between one of the coils and the imaging element also attracts magnetic field noises generated from the other coil. In such a case, there is such a problem that an amount of magnetic field which arrives at the imaging element cannot be sufficiently reduced.